Search

Backgrounds Long non-coding RNA is a novel group of non-protein coding transcripts over 200 nt in length. Recent studies have found that they are widely involved in many pathological and physiological processes. In our previous study, we found that lnc-GULP1–2:1 was significantly down-regulated in the ovarian cortical tissue of patients with primary ovarian insufficiency and predicted that lnc-GULP1–2:1 has a regulatory effect on COL3A1. Results In this study, we found that lnc-GULP1–2:1 was mainly localized in the cytoplasm of luteinized granulosa cells. The expression of lnc-GULP1–2:1 was lower in patients with diminished ovarian reserve but substantially elevated in patients with polycystic ovary syndrome. Overexpression of lnc-GULP1–2:1 in KGN cells significantly inhibited cell proliferation, likely through cell cycle related genes CCND2 and p16. Moreover, lnc-GULP1–2:1 expression was positively correlated with the level of COL3A in luteinized granulosa cells from patients with different ovarian functions as well as in multiple cell lines. Overexpression of lnc-GULP1–2:1 in KGN cells promoted the expression of COL3A1 and its translocation into the nucleus. Consistently, silencing COL3A1 in KGN cells also significantly inhibited cell proliferation. Conclusions Lnc-GULP1–2:1 affects the proliferation of granulosa cells by regulating the expression and localization of COL3A1 protein, and may participate in the regulation of ovarian follicle development. This study will provide new insight into molecular mechanisms underlying ovarian follicular development, which will help generate novel diagnostic and therapeutic strategies for diseases related to ovarian follicular development disorders.

A disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1) is an extracellular matrix metalloproteinase that plays an important role in the process of ovulation. According to previous studies, the expression level of ADAMTS1 in the granulosa cells of polycystic ovarian syndrome (PCOS) patients and the mechanism for regulating oocyte quality and embryonic development potential are still unclear. Our research clarified that ADAMTS1 was significantly increased in granulosa cells of PCOS patients as compared to ovulatory controls. After silencing ADAMTS1 in granulosa cells, cell proliferation and E2 secretion were significantly inhibited, which may be related to the down-regulation of B-cell lymphoma 2 (Bcl2) family genes and key genes involved in E2 synthesis. Through retrospective analysis of the clinical data, it was found that the expression level of ADAMTS1 was significantly positively correlated to the oocyte maturation rate and good-quality embryo rate in PCOS patients. The downregulation of ADAMTS1 in primary granulosa cells lead to the changes in the expression of marker genes for oocyte and embryonic quality. By using immunofluorescence staining, it was found ADAMTS1 was expressed in various stages of pre-implantation embryo but its expression level gradually decreases with the development of the embryo. In addition, the silence of ADAMTS1 in 3PN zygotes significantly prolonged the development time of the zygote to the morula stage. This is, to our knowledge, the first time to explored the mechanism by which ADAMST1 is involved in affecting the quality of oocytes and embryonic development potential, which will provide new evidence for further understanding of the follicular microenvironment and embryo development.

Mammalian ovarian follicular development is an intricate, elaborate, and well-organized phenomenon regulated by various signaling pathways; however, the underlying mechanism remains unclear. Mammalian sirtuins (sirtuin 1 to sirtuin 7) are a group of NAD+ -dependent deacetylases implicated in various physiological processes including cell proliferation, apoptosis, cell cycle progression, and insulin signaling. Mammalian ovarian sirtuins have been studied using adult and aged bovine, porcine, and murine models. However, limited information is available regarding their precise expression patterns and the localization of follicle development in mice. This study aimed to assess the dynamic expression and localization of all seven sirtuins in early postnatal mouse ovaries through real-time polymerase chain reaction analysis and immunohistochemistry, respectively. During postnatal ovarian follicle development, sirtuin 1, sirtuin 4, and sirtuin 6 were downregulated compared with those in 1-day postnatal mouse ovaries (p < .05), indicating that these three sirtuin genes may be markers of follicular development. Combining their localization in granulosa cells through immunohistochemical studies, sirtuin 1, sirtuin 4, and sirtuin 6 are suggested to play negative regulatory roles in mammal ovarian follicular granulosa cell development. Furthermore, we found that sirtuin 2 (p < .05) and sirtuin 7 (p < .05) mRNA were constantly upregulated relative to sirtuin 1, although limited information is available regarding sirtuin 7. Among all sirtuins in mouse ovaries, sirtuin 1 was relatively and steadily downregulated. Upon sirtuin 1 overexpression in 1-day postnatal mouse ovaries via sirtuin 1-harboring adenoviruses in vitro, the emergence of primary follicles was delayed, as was the emergence of secondary follicles in 4-day postnatal ovaries. Further studies on KGN cell lines reported that interfering with sirtuin 1 expression in granulosa cell significantly affected granulosa cell proliferation and the expression of mitochondrial genes. This study presents the first systemic analysis of dynamic patterns of sirtuin family expression in early postnatal mice ovaries, laying the foundation for further studies on less discussed sirtuin subtypes, such as sirtuin 5 and sirtuin 7.

Seasonal acclimatization is important for animals to live optimally in the varying environment. Phrynocephalus vlangalii, a species of lizard endemic in China, distributes on Qinghai-Tibet Plateau ranging from 2000 to 4600m above sea level. To dissect how this lizard mediate metabolism to adapt various season, the preferred body temperature (Tb), standard metabolic rate (SMR), mitochondrial respiration rates and activities of four metabolic enzymes in this species were tested in different seasons (spring, summer, and autumn). The results showed that the preferred Tb was the lowest in spring and the highest in summer. SMR, maximal mitochondrial respiration rates in liver and skeletal muscle were the highest in spring. Similarly, higher activities of lactate dehydrogenase (LDH), citrate synthase (CS) and cytochrome c oxidase (CCO) activities of liver and skeletal muscle were observed in spring. However, β-hydroxyacyl coenzyme A dehydrogenase (HOAD) activities of liver and skeletal muscle were higher in autumn. On the whole, seasonal variation of metabolism is the highest in spring and the lowest in summer. Seasonal variation of metabolism is the opposite of preferred body temperature, this may be one of the mechanisms to adapt to the environment in P. vlangalii. Our results suggested that P. vlangalii at high altitude has certain adaptive characteristics on metabolism in different seasons.

Nitric oxide (NO), produced by nitric oxide synthases (NOS) from L-arginine, plays important roles in a wide range of physiological processes. However, little is known about ectothermic species. To investigate the response of NO/NOS system in adaptation to different altitudes in Phrynocephalus genus, the red tail toad-headed lizard Phrynocephalus erythrurus that live at 4500-5300 m on the Qinghai-Tibet Plateau and another low altitude living lizard Phrynocephalus przewalskii were selected in the present study. The results of mRNA expression and activity of NOSs, as well as NO metabolite levels in different tissues of the two lizards indicate that nNOS mRNA levels in cardiac and skeletal muscle were notably elevated in P. erythrurus, and iNOS expression was also increased markedly (up to 4-fold) in cardiac muscle. There was no significant difference in eNOS mRNA level in tested tissues between two species. However, the total NOS activity in skeletal muscle of P. erythrurus was slightly lower than that of P. przewalskii (p .05) while no difference in other tissues. Similarly, lower iNOS activity (p .01) was found in cardiac and skeletal muscle in P. erythrurus compared to P. przewalskii. In addition, the NO metabolite levels were dramatically lower in P. erythrurus in all tested tissues. We propose that higher nNOS and iNOS mRNA expression, lower iNOS activity and NO metabolite levels may represent physiological characteristics in nitric oxide system, which may contribute to high-altitude adaptation in P. erythrurus.